1. Field of the Invention
The present invention relates to a spiral coil for simplified bookbinding and a bookbinding device and method.
2. Description of the Related Art
According to one of known bookbinding techniques, a plurality of sheets is bound to one book by punching a plurality of holes in each sheet at a certain spacing and inserting a spiral coil through the holes, the spiral coil being wound at a constant pitch. Major advantages of that bookbinding technique are as follows: First, the bound book can be opened at 360 degrees. Secondary, high durability is ensured by using a coil made of metal or plastic. Another major advantage is that the production cost can be held relatively low.
However, conventional bookbinding techniques have a problem in that sheets and spiral coils have different pitches for bookbinding using a constant-pitch spiral coil, which is not standardized. More specifically, there are various pitches, resulting in inconvenience of erroneously using a spiral coil with a 6-mm pitch for a sheet having holes at a 5-mm spacing. Furthermore, the 6-mm-pitch spiral coil that is erroneously selected is not recoiled to an appropriate 5-mm pitch, which frequently occurs for personal consumers having no special equipment or dedicated machine.
In general, after the spiral coil has been inserted through the holes of the sheet, the spiral coil is bent at the ends for terminal treatment. In this case, it is well known that conventional art terminal treatment has the following drawbacks.
(1) It is difficult to reuse the spiral coil because of the bent ends. It is because it is generally difficult to restore the bent material made of metal or plastic into an original shape.
(2) It is difficult to take the bound sheets in and out again because the spiral coil is bent to be secured at a fixed position, thus making it difficult to change the order of the bound sheets.
(3) A dedicated device and labor are generally required to bend the spiral coil at the ends.
In other words, the conventional art bookbinding operation using the spiral coil has problems in that the sheets and the spiral coils vary in pitch and the reuse thereof is difficult.
The present invention has been made in consideration of the above problems; accordingly, it is an object of the present invention to provide a spiral coil and a bookbinding device using the spiral coil, which is easy to use with a simple structure and is able to perform bookbinding using a spiral coil that is coiled at a different pitch from the spacing between a plurality of holes punched in sheets. Another object of the present invention is to provide a new bookbinding method for integrally binding a plurality of sheets using the spiral coil and the bookbinding device.
In order to achieve the above objects, according to a first aspect of the present invention, there is provided a spiral coil used when stacking a plurality of sheets each having a plurality of holes punched at a constant pitch, and binding the plurality of sheets together by inserting the spiral coil through each of the holes, wherein the spiral coil is plastically deformed to have a different pitch from that between the holes in an unused state, and to have the same pitch as that between the holes during use.
With such a configuration, a plurality of sheets can be bound by the plastic deformation of the spiral coil irrespective of difference between the spacing between the holes punched in the sheets and the pitch of the spiral coil.
According to the present invention, preferably, the spiral coil is a variable-pitch spiral coil in an unused state.
With such a configuration, a plurality of sheets can be bound using the spiral coil wound at a variable pitch, such as a densely spiraled coil having high portability, a spiral coil wound at a different pitch, and a spiral coil used in different fields.
According to a second aspect of the present invention, there is provided a bookbinding device used when stacking a plurality of sheets each having a plurality of holes punched at a constant pitch, and binding the plurality of sheets together by inserting the spiral coil according to the first aspect of the invention through each hole, wherein the bookbinding device has a spiral shape wound at the same pitch as that between the plurality of holes and has an engaging portion formed in at least one end thereof for engaging with an end of the spiral coil.
With such a configuration, a bookbinding device can be provided to an individual consumer for binding a plurality of sheets by inserting a compact and easy-to-use spiral coil therethrough without the need for a large dedicated bookbinding device or a special work.
According to the present invention, preferably, the engaging portion has a shape different from the end of the spiral coil, and the end of the spiral coil is inserted into the engaging portion for engaging with each other.
With such a configuration, the spiral coil and the bookbinding device can easily be brought into engagement with each other only on the basis of the outer shapes without the need for special operation.
According to a third aspect of the present invention, a plurality of sheets each having a plurality of holes punched at a constant pitch is stacked and bound into one book using the spiral coil according to the first aspect of the invention and the bookbinding device according to the second aspect of the invention.
With such a configuration, there is provided a bookbinding method for binding a plurality of sheets into one book by inserting the spiral coil therethrough with an exceedingly simplified device without the need for a well-known electric or large bookbinding device.
The simplified bookbinding device using the spiral coil according to the present invention is in principle configured as described above. The spiral coil is preferably made of metal, such as iron. The plastic deformation is performed only by a simple operation at room temperature and normal pressure. One major feature is that since the bookbinding device and the spiral coil differ in diameter and pitch at the engaging portion of the bookbinding device, both are brought into frictional engagement with each other within the elastic limit. Furthermore, a storage case may be provided for enclosing the plurality of spiral coils or the bookbinding device according to the present invention.